Overview
ISO 21572:2019 - Foodstuffs: Molecular biomarker analysis - Immunochemical methods for the detection and quantification of proteins - specifies performance criteria and analytical considerations for immunochemical methods used to detect and/or quantify specific protein(s) of interest (POIs) in food and related matrices. The standard covers general principles, sample preparation, extraction, assay procedures (including ELISA and lateral flow devices in Annexes A and B), interpretation of results and relevant performance parameters for protein detection and quantification.
Key topics and technical requirements
- Scope and principle
- Focuses on immunochemical assays that use antibody–antigen binding to detect or quantify target proteins extracted from a representative sample.
- Sample preparation & extraction
- Guidance on preparing representative test portions, grinding, extraction buffers and matrix-appropriate procedures. Emphasises validated extraction methods and proper storage of extracts.
- Reagents and equipment
- Use of analytical-grade reagents and low protein-binding laboratory consumables; storage and shelf-life of kits (LFDs, antibodies, conjugates) must be specified.
- Assay setup & calibration
- Procedures for preparing calibration curves, positive/negative controls and matrix-matched reference materials for quantitative assays (ELISA). Qualitative tests (LFDs) may use controls at analyst discretion.
- Performance parameters to evaluate
- Selectivity, extraction efficiency, matrix effects, assay applicability, hook effect, parallelism/linearity, limits of detection (LOD) and limits of quantification (LOQ).
- Quality assurance and reporting
- Recommendations on laboratory QA (referencing ISO/IEC 17025), double determinations, blanks, calibration, confirmatory testing and required elements of the test report.
- Annexes
- Practical example procedures for ELISA (Annex A) and lateral flow devices (Annex B).
Practical applications
ISO 21572:2019 is directly applicable to:
- Allergen testing and labelling verification
- Detection of newly expressed proteins in biotech crops (GMO monitoring)
- Food safety screening and quality control during food processing and marketing
- Biotechnology product testing and disease indexing where specific protein biomarkers are analysed
- Development and validation of immunoassay-based kits (ELISA and LFD manufacturers)
Who should use this standard
- Food testing laboratories and quality assurance teams
- Regulatory and inspection authorities
- Diagnostic and kit manufacturers (ELISA, LFD)
- Researchers in food safety, molecular biomarker analysis and biotechnology
- Producers and processors implementing protein-based testing for compliance or product claims
Related standards
- ISO 16577 - Molecular biomarker analysis - Terms and definitions
- ISO/IEC 17025 - General requirements for the competence of testing and calibration laboratories
Keywords: ISO 21572:2019, immunochemical methods, protein detection, ELISA, lateral flow devices, molecular biomarker analysis, food safety, allergen testing, matrix effects, limits of detection.